Rodmonster

I just put ZO6 NPP Exhausts on the normal non-NPP stingray, sounds great, but I am not sure why the Check engine light came on. I asked the muffler shop if they plugged in the cable After I drove off. They said No. Any quick fixes to get rid of the Check Engine light?

ht_pro

Hey, since yours in Non-NPP, are the valves always in 1-position? IE either closed or open? Might have something to do with AFM (active fuel management)? I think that the cable should be plugged in....and maybe get a tuner, check the codes.

Rodmonster

so I put C7 Z06 NPP exhaust on my C7 Stingray. the check engine light came on, because the cable was not long enough to reach the Z06 exhaust port. As the location of the port is different on the Z06 exhaust vs base stingray exhaust. I took my car to a performance shop out in LA, the performance shop extended the cable for a very reasonable fee.

FYREANT

wow. What they did was all kinds of wrong. you CANNOT use a Z06 NPP exhaust on a stingray!! I just sent this same thing to ht_pro:


All non-Z06 C7's have at least one set of exhaust valves. The first set is the AFM valves (related to Eco mode), which are located before the mufflers. The C7 NPP exhaust has a second set of valves after the mufflers. It is not possible to "delete" the first set of valves as your BCM is programmed to check them at each start up. These CANNOT be "turned off" in your tune.

The Z06 does NOT have AFM valves at all, JUST the valves after the muffler.

As a result the Z06 mufflers have NO way to mount your AFM valves (which again cannot be deleted) as the Z06 muffler simply do not have the flaps and mount for the AFM.

What you have to keep in mind is that your car does not have the actual wiring to use an NPP exhaust. When you get under the car, there is actually no connectors for you to simply plug it in.

The below picture will hopefully make more sense.

The valves by the red arrow are the AFM valves, the valves by the exhaust tips are the NPP sound valves.

All C7 (non Z06) have the red valves
Only C7 with NPP have the green valves
All Z06 have the green valves. They do NOT have the red valves.

these two different valves are exactly that. They are different. You cannot plug the cable for the AFM into the NPP. While the connector will fit, the valves serve different purposes and are not doing what you think they are doing lol.

16Stingray

FYREANT,
I thought there was a way to turn off the AFM so it would stop going into 4 cylinder mode via a tuner like diablo, is that not true>

7LitreC5

You can turn off AFM in the tune but not the AFM valves.

FYREANT

^^^ This.

ht_pro

Shoot! So what happened in Rodmonster's case to the functionality. I get that he plugged the AFM cable into the NPP harness. But now what is it actually doing? Thanks for the notice, Ant!

FYREANT

Hard to say exactly what it's doing. It's going to try to control the valves based on how he's driving the car and the driving mode that he is in. Not based on sound demand. Im sure its acting funky compared to normal though lol. He may not even notice what its doing..

16Stingray

If the AFM is tuned out then what are the AFM valves doing? They are still being opened and closed?

7LitreC5

They should be open all if the time since it is not in V4 mode at all.

robert miller

Ant, since he has the z06 stuff on the car plus the cost of that also. Cant he just have the muffler shop to cut his front ones before the mufflers from his pipes & have them welded into the z06 pipes & every thing be good again. Robert

7LitreC5

Didn't somebody have AFM valve simulators for sale at one time? I thought that I had seen that in the past but I may not be remembering correctly.

FYREANT

Could you do that? Yes. But thats a lot to go through IMO.

Yes, EdgyVette had them but they are no longer available..